The present invention generally pertains to a subscriber communicator for use in satellite communications and is particularly directed to an improved implementation of the receiver and transmitter channels of a subscriber communicator in an ASIC (application specific integrated circuit).
In a subscriber communicator, the receiver channel downconverts and demodulates a received RF (radio frequency) communication signal to provide received quadrature components at baseband and processes the quadrature components to respectively provide I and Q digital data output signals; and the transmitter channel processes I and Q digital data input signals to provide input quadrature modulation components; and upconverts and combines the quadrature modulation components to provide an RF communication transmit signal.
A known RF ASIC for a subscriber communicator comprises a receiver section that includes means for receiving an RF communication signal and means for directly downconverting and demodulating the received RF communication signal to provide analog quadrature components of the received signal at baseband; a transmitter section that includes means for upconverting and combining analog input quadrature modulation components to provide an RF communication transmit signal and means for amplifying the transmit signal for driving an external power amplifier; and a synthesizer for providing signals at selected frequencies for use in said downconversion and upconversion.